Fume dispersing work lamp



May 5, 1970 R. L. MAY 3,510,228

FUME DISPERSING WORK LAMP Filed April 24, 1967 United States Patent Ofi 3,510,228 Patented May 5, 1970 ice US. Cl. 415-121 6 Claims ABSTRACT OF THE DISCLOSURE A lamp with an annular light source is provided with an exhaust fan mounted inside the light source. A reflector is mounted behind the light source. The housing of the lamp and fan assembly acts as a baffle to limit recirculation of the exhausted gases. The lamp housing is mounted on movable support arms for ease in adjusting the lamp with respect to the desired illuminating surface.

BACKGROUND OF THE INVENTION The importance of adequate lighting for artistic, scientific and industrial work has become well recognized. Many specialized forms of lamps have resulted. For work of a fine and intricate nature, lamps mounted on jointed arms or goosenecks have found increasing use for bringing an illuminating source close to a work piece. One specialized form of lamp uses a circular fluorescent tube with a large magnifying lens mounted concentrically permitting magnified viewing of a work piece through the center of the illuminating source.

The electronics industry today requires a great deal of fine intricate circuit wiring requiring the use of solder. Acid etching is also used today in a lot of fine work. Sometimes these things can be entirely mechanized, eliminating human problems, but this is not always possible. The smoke and acid fumes from soldering and acid etching and the like not only are deleterious to the health, but they also tend to obscure vision and distress the operator so as to retard and degrade the work product. The lamp of the present invention is designed to overcome this problem.

In the past it has been common to use concentric ventilating channels in a lamp for cooling the lighting element as for example in US. Pat. No. 2,069,950 to Greppin. Kitchen hoods for capturing range fumes have been made with both lights and exhaust fans within the hood, for example see U.S. Pat. No. 3,064,551 to Stalker. None of these are really relevant to the present invention. The first without a fan would not easily disperse fumes and even with a fan it needs something additional to adequately handle the dispersal of noxious fumes as opposed to merely cooling the lamp element. The second is a fixture and has no real relation to a work lamp, nor does it make use of the coaxial arrangement of the invention.

Three patents U.S. Nos. 3,180,981 to Ultlers, 3,168,985 1 to Troup et al., and 2,562,600 to Caldwell, et al. all show lamps mounted together with fans for cooling the lamp elements. These are not work lamps and none of them show a ring-shaped or annular lamp element with a fan exhausting coaxially therethrough. Again none of them are capable of adequately collecting fumes and gases from the direction of the illuminating beam and dispersing them in the opposite direction in the manner of the present invention as will be understood from the following description.

Thus it is an object of the invention to define a novel combination of an illuminating source and an exhaust fan. It is a further object of the invention to define a work lamp in which the light source is annular in shape and in which an exhaust fan is disposed to draw gasses through the center of the annulus. It is a further object of the invention to define a lamp arrangement with a coaxially mounted fan that minimizes noise and vibration while exhausting fumes from an illuminated work area.

DESCRIPTION OF THE INVENTION Further objects and features of the invention will become apparent upon reading the following specification together with the drawings in which:

FIG. 1 depicts a side elevation of a complete work lamp in accordance with the invention;

FIG. 2 depicts a partial cross section of the lamp head of the lamp of FIG. 1;

FIG. 3 is a bottom view of exhaust fan 28 of FIG. 2.

FIG. 1 depicts an exhaust lamp unit according to the invention in which the lamp head 10 is connected by support stud 11 to two elongated arms 12. Arms 12 are connected to st-ud 11, to each other and to lamp base 16 by rotatable joints, 13, 14 and 15 respectively. As depicted, these joints are fitted with thumb screw locking means to secure them in a selected position. However, spring loading of the joints is used in an alternative arrangement to avoid the necessity of tightening and loosening thumb screws. Conventional gooseneck arrangements are also suitable for the invention.

Base 16 serves as a mounting base for the entire lamp assembly and may be supplied with a bench-clamp 17 for clamping it securely to a table or bench-top. Base 16 may also contain a fluorescent lamp ballast unit (not shown) and a switch 18 for operation of the exhaust fan.

FIG. 2 illustrates lamp head 10 in detail. Housing 20 is made of a generally U-shaped channel member curved in annular form so as to provide a recess adapted to receive an annular light bulb. Mounted from an inner side wall of housing 20 and extending across the channel is a reflector 21. Attached to reflector 21 are a number of support straps 44 adapted to support an annular light bulb 22 in close proximity to reflector 21. Reflector 21 and housing 20 are adapted to direct light from said bulb in a beam having an angular width less than degrees.

Housing 20 forms an annulus around a central opening. Secured to housing 20 in this central opening is fan housing 23 also having an annular shape. The bottom edge of fan housing 23 is bent into an outwardly extending flange 25. For purposes of the present application, the word bottom is used to describe that portion of an element or part that is most proximate to the end of the present lamp from which light is radiated. Thus, for example, the U-shaped channel is inverted so that the bottom of the U is open to pass light while the top of the U is closed. Flange 25 rests on an inwardly extending shelf 26 formed in the inner sidewall of housing 20. A gasket 45 may be inserted between flange 25 and shelf 26 to provide a resilient fit with less chance of vibration noise. Annular spring clip 27 is forced down against flange 25 until it spreads to lock into a small recess in housing 20, securing fan housing 23 in the central opening of housing 20. The top of fan housing 23 is bent to form an inwardly extending top flange for mating with the top flange of fan casing 31. Bolts 29 extend through the top flange of fan housing 23 and into threaded apertures in casing 31 for securing fan assembly 28 to fan housing 23,

Decorative grill 32 also mounted from bolts 29 protects the top of the fan from the intrusion of articles into rotating blades.

Referring to FIG. 3, fan blades 33 are mounted on a single hub revolving about fan motor 35. Motor 35 is supported at the bottom by radial arms 36 extending to casing 31.

An enlarged radial support arm 37 for motor 35 has an interior passage for electric leads 39. As shown in FIG. 2, leads 39 reach fan assembly 28 through an aperture 40 in housing 20. Aperture 40 contains a grommet 46. Both leads 39 and leads 41 for electrical connection to light bulb 22 enter housing 23 through a passage 42 in stud '11. Leads 39 and 41 pass from stud 11 inside housing 20 above reflective element 21 whereby they are substantially hidden from view. Leads 39 and 41 are double leads and one of leads 41 (not shown) connects to light bulb 22 through switch 43.

The particular fan arrangement utilized in a preferred embodiment of the present invention is remarkable in that it operates with essentially free delivery and little noise or vibration. For free delivery it is necessary to eliminate the use of filter, or extended passages for controlling the air flow. Such passages reduce the total air flow and make necessary greater driving power to attain a predetermined flow volume. In a preferred embodiment of the present invention there is no passage extension beyond the trailing edges of blades 33. The trailing edges of blades 33 are substantially even with the termination of the air flow passage of casing 31. As depicted in FIG. 2, fan housing 23 terminates together with casing 31. Extended passages are sometimes necessary to limit recirculation. The type of lamp used in the present invention provides a relatively large diameter housing which acts as a baffle limiting recirculation. At the same time it offers substantially no restriction to air flow.

In order for the housing to be effective in limiting recirculation, the housing diameter should be relatively large compared to the fan diameter from blade tip to blade tip. It has been found satisfactory to have the lamp housing diameter about three or more times the tip to tip diameter of the fan. With this limitation, a fan delivering about 30 cubic feet per minute or more has been found adequate for dispersing most fumes.

A well-designed fan having a diameter from blade tip to blade tip of three inches or more has been found capable of delivering the required air flow with a noise and vibration level low enough to pass unnoticed under most working conditions.

It was originally thought that some sort of chimney would be required to conduct fumes a distance away. This in turn required a larger fan with objectionable noise in -order to provide the necessary exhaust flow. By chance it was discovered that fumes were dispersed so quickly by the fan operating into free delivery that fumes were virtually unnoticeable at the delivery end of the fan.

A particular advantage of the present invention is that the air flow carrying fumes from a work area also produces a cooling fiow of air over the light bulb reducing both heat and fumes in the vicinity of said lamp. This has been found to make it easier for personnel to work in close proximity to the lamp Without the usual heat annoyance. The lamp bulb lifetime of course is increased as well.

While the invention has been described with relation to a specific embodiment, many obvious variations thereof are contemplated and it is intended to cover the invention broadly within the spirit and scope of the appended claims.

I claim:

1. A work lamp having in combination an exhaust fan and an illumination source comprising:

(a) lamp housing means supporting a substantially annular light source, said housing means having an opening lying along the central axis perpendicular to the plane of a light source supported therein, wherein the length of said light housing is relatively shorter than the diameter of said light housing;

(b) reflector means mounted to said housing means for directing light from the light source supported by said housing means;

(c) a motor-driven rotary fan mounted in said opening comprising multiple blades mounted for rotation on a single hub with the fan diameter from blade tip to blade tip being at least three inches and not more than one-third the diameter of said housing in the plane of said blades, said fan blades terminating substantially in the same plane as the end of said lamp housing, said fan exhausting gases from the direction in which said reflector means directs light and for dispersing said gases in the opposite direction, and wherein the diameter of said lamp housing acts as a battle limiting recirculation.

2. The combination according to claim 1 in which said housing means further comprises a base for mounting said combination rigidly to a mounting surface and jointed support arms adapted to permit movement of a supported light source and fan relative to said base.

3. The combination according to claim 2 in which said light source is a circular fluorescent tube mounted on said reflector means.

4. The combination according to claim 3 in which said fan comprises a fan casing and multiple impellor blades, each having leading and trailing edges on a single hub mounted for rotation in said casing with said trailing edges terminating substantially even with said casing.

5. The combination according to claim 1 in which said reflector means is adapted for directing light in a beam having an angular width less than degrees.

6. The combination according to claim 5 in which said fan is adapted to simultaneously exhaust fumes from the direction of said beam and produce a cooling flow of air over a source of illumination mounted in said housing whereby both heat and fumes are reduced in the vicinity of said lamp.

References Cited UNITED STATES PATENTS 2,201,153 5/1940 Brown.

2,506,575 5/1950 Brandeis 240-51.l2

2,581,185 1/1952 Gordon 24051.12 XR 3,039,678 6/1962 Sharpe 2405l.l2 XR 3,066,219 11/1962 Duddy 24047 FOREIGN PATENTS 1,264,759 5/1961 France.

NORTON ANSHER, Primary Examiner LEO H. MCCORMICK, JR., Assistant Examiner US. Cl. X.R. 

